In a bizarre ritual, an amorous male hides on the underside of a leaf and thrusts the paddle high enough for a female on the other side of the leaf to see it. The researchers know of no other jumping spider that conducts such a peekaboo courtship—nor of one that has built-in paddles on its legs, according to a study published January 7 in the journal Peckhamia.

Study co-author and independent spider expert David Hill has scrutinized a lot of spiders, but this one “is the most amazing one I’ve seen,” he says. “It’s quite a remarkable creature.”

Jumping spiders are well known for their elaborate courtships and fancy features, says entomologist Robert Matthews, a professor emeritus at the University of Georgia. But even among their tribe, the newfound spider's paddle-waving is “really unusual,” he says via email.

The new spider and its weird love antics might have remained unknown to science if Jürgen Otto had stayed at home between Christmas and New Year’s Eve in 2014.

Instead Otto, who is a mite expert in his day job with the Australian government and a spider scholar in his free time, went camping at a national park outside Sydney. For the first time ever, he deliberately left at home the camera he uses to snap portraits of Australian creepy-crawlies.

After returning from the camping trip, Otto found a spider on his tent. The animal seemed nondescript—until he saw its odd-looking legs. Otto surrendered to his fate.

Two days later, he drove four hours back to the campsite, searched nearly an entire day, and finally found more of the strange-looking spiders. He identified them as a new species, Jotus remus, the latter part of which means "oar" or "paddle" in Latin.

"Extraordinary Game"

Even with plenty of specimens to study at leisure, Otto couldn’t figure out how the spider used its namesake appendage. The paddles, made of soft, fine bristles, were of no use to the spider as it jumped or tried to swim.

Finally, Otto put male and female spiders together. After a bit of experimentation, he found that a male jounces the leaf occupied by a female as well as waggling his paddles at her seductively. (See "New 'Blue Face' Peacock Spider Is Fancy Dancer.")